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Dinosaur Home A-Z Dinosaurs List Dinosaurs
Dinosaurs
Knowledge about dinosaurs comes from both fossil and nonfossil records,
including fossilized
bones,
feces, trackways, gastroliths, feathers,
impressions of skin, internal organs and "soft tissues”. Dinosaurs
are animals that dominated the terrestrial ecosystem
for over 100 million years.The term is also used informally to describe
any prehistoric reptile, such as the pelycosaur Dimetrodon, the winged
pterosaurs, and the aquatic ichthyosaurs, plesiosaurs, and mosasaurs,
though none of these are dinosaurs.
Since the first dinosaur was recognized in the 19th century, their mounted
skeletons have become major attractions at museums around the world. Dinosaurs
have become a part of world culture and remain consistently popular, especially
among children. They have been featured in best-selling books and blockbuster
films such as Jurassic Park, and new discoveries
are regularly covered by the media. Non-avian dinosaurs became extinct
at the end of the Cretaceous period, 65 million years ago.
The on-going dinosaur renaissance began in the 1970s and was triggered,
in part, by John Ostrom's discovery of Deinonychus-- an active, vicious
predator that may have been warm-blooded (homeothermic), in marked contrast
to the prevailing image of dinosaurs as sluggish cold-blooded reptiles.
Vertebrate paleontology has also become a global science, with major new
discoveries in previously unexploited regions, including South America,
Madagascar, Antarctica, and most significantly the amazingly well-preserved
feathered dinosaurs in China, which have
further solidified the link between dinosaurs and their living descendants,
the 9,000+ species of modern birds. The widespread application of cladistics,
which rigorously analyzes the relationships between biological organisms,
has also proved tremendously useful in classifying dinosaurs, which are
still known from an incomplete fossil record.
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